I had previously been using signs as a layer to hold water in a chicken coop (the chickens float in the water and drop eggs through), and underneath the layer of signs I had another layer of water which sweeps all the eggs out to one end. However when I stacked my signs to build a coop today, they broke when I removed the layer underneath.
I think I can still walk under the chickens to collect the eggs by stacking 2 signs on top of each other in each square of the coop, but water can no longer flow underneath to sweep them out of the coop.
How can I make the signs float? Or is there something else I can use instead as a layer that holds water but lets eggs through?